Electrical Component

ABSTRACT

An electrical component, e.g., a diplexer or a duplexer, can have one of a number of diverse arrangements for terminal surfaces on the substrate bottom. For example, the terminal surfaces for first and second filters are not disposed at the maximum distance from one another. First and second filters can be disposed as one or two discrete components on the substrate, wherein one filter can be implemented as being integrated in a multilayer substrate.

This application is a divisional of application Ser. No. 12/731,039filed on Mar. 24, 2010, which is a continuation of co-pendingInternational Application No. PCT/EP2008/062971, filed Sep. 26, 2008,which designated the United States and was not published in English, andwhich claims priority to German Application No. 10 2007 046 728.3 filedSep. 28, 2007, all of which applications are incorporated herein byreference.

TECHNICAL FIELD

The invention relates to an electrical component comprising a first anda second filter, for example, a diplexer or a duplexer, implemented inor mounted on a common substrate.

BACKGROUND

A duplexer, including an advantageous footprint, is known, for example,from WO 2007/059735 A.

SUMMARY

In one aspect, the present invention discloses an improved pinning orfootprint for a component, by means of which further miniaturization ofthe component is possible without degrading the electrical performanceof the component.

In one embodiment, an electrical component is specified, which includesa first and a second filter implemented or mounted on a commonsubstrate. The substrate has a common signal connection on the bottomside, to which both filters are connected in parallel. A first and asecond filter connection for the first and second filter is alsoprovided on the bottom side. Every signal or filter connection on thebottom side is characterized in that an individual terminal surfaceconducting a signal, or alternatively a pair of terminal surfacesbalanced to each other with respect to ground is assigned to it, theterminal surfaces implementing the respective connection to the filteror the component. A plurality of ground terminal surfaces is alsodisposed on the bottom side. At least one of the ground terminalsurfaces is disposed in a corner, and is further away from a terminalsurface of the signal connection than a terminal surface of the filterconnections. In other words, the distance between a terminal surface ofthe signal connection and a terminal surface of a filter connection isless than the distance between a ground terminal surface in the cornerand a terminal surface of the signal connection. Altogether, thefootprint includes at least seven terminal surfaces disposed near theedges of the substrate, which is, for example, rectangular, the terminalsurfaces being associated with one of the types of terminal surfacesnamed above.

Three different connections, each having at least one terminal surfaceassigned to the connection, are provided in the electrical component,while the remainder of the terminal surfaces that are present are groundterminal surfaces. In the component at least one ground terminal surfaceexists that includes a maximum distance to a signal terminal surface,wherein the distance is greater than or equal to the maximum distancebetween a signal connection and an arbitrary filter connection. Thismeans that not all filter connections include the maximum distance tothe signal connection.

In one embodiment, the component includes terminal surfaces in anarrangement corresponding to a grid of at least 3×3 on the bottom sideof the substrate. To this end, the terminal surfaces can be disposed inrows and/or columns. The arrangement is not, however, required to besymmetrical. Individual columns and/or rows can be present that have agreater number of terminal surfaces than the other rows and/or columns.The terminal surfaces can, in particular also have different sizes. Itis advantageous, but not required, if the ground terminal surfacesinclude a greater area than the signal and/or filter terminal surfaces.

In one embodiment, the component includes a pair of electrical terminalsurfaces balanced to each other with respect to ground, wherein the twoterminal surfaces of the pair are disposed directly adjacent to eachother. The component can also include two or three pairs of terminalsurfaces balanced to each other with respect to ground, wherein theterminal surfaces of each pair are disposed directly adjacent to eachother.

It is advantageous if all signal and filter terminal surfaces aredisposed in an edge area on the bottom side of the substrate. At leastone ground terminal surface can then be present in a center area. Here,a terminal surface is considered to be disposed in the edge area if itis disposed in one of the rows and/or columns pointing outwards, of anarray of terminal surfaces that is at least 3×3 in size. Following theouter perimeter of the substrate, that is, between the signal and eachof the filter connections, and between the first and second filterconnection at least one ground terminal surface is provided in the edgearea. In the center area, which is enclosed by the edge area and theterminal surfaces disposed there, at least one centrally disposed groundterminal surface is provided.

The surface area of at least one ground terminal surface preferablyexceeds that of the signal or filter terminal surfaces, so that animproved ground connection is provided solely by the greatermetallization.

A smaller area of a filter connection leads to a lower capacitanceassociated with the area, so that the terminal surface can incur only alower capacitive coupling.

According to one variant, the at least one terminal surface of thesignal connection is disposed in the center of one of the substrateedges. The row of terminal surfaces in which the signal connection isdisposed then includes at least two ground terminal surfaces on bothsides of the signal connection, and thus, includes a total of at leastthree terminal surfaces.

The component is preferably formed as a diplexer or duplexer. In thiscase, the signal connection is connected to an antenna connection, oritself implements the antenna connection. The two filter connections areaccordingly formed as filter input and/or filter output.

In order to improve the ground connection, each ground connection oreach ground terminal surface can be connected to one of the two filters,or to both filters, by a plurality of vias. The inductivity of theground connections is thus also minimized. The terminal surfaces of thesignal and filter connections, in contrast, are advantageously connectedto the corresponding filter by only exactly one via each.

According to one variant embodiment, at least one of the filterconnections includes a pair of terminal surfaces balanced to each otherwith respect to ground, and disposed at different distances from thesignal connection. The terminal surface of the pair that is disposedcloser to the signal connection includes a smaller surface area than theother terminal surface of the pair. This has the effect that thecapacitive coupling between the different terminal surfaces, which tendsto be greater at shorter distances, is again reduced by the smallerarea. In this manner, both terminal surfaces of the connection pair canbe formed having approximately equal coupling to the signal connectionor the signal terminal surface.

In order to improve the ground, it is further proposed that at least twoof the ground terminal surfaces are electrically conductively connectedto each other directly on the bottom side of the substrate. This can bedone by means of conductors applied to the bottom side. In this manner,the ground is “enlarged” and any possible difference in the quality ofground connections is leveled by the electrical connection and thuscompensated for.

The connections of the component are connected, as mentioned, to thecorresponding filters by means of vias passing through the substrate.For each filter connection, the via connected to the filter connectionis routed directly adjacent to a via connected to a ground connection ofthe same filter, wherein the distance of the via leading to the filterconnection is greater than the distance of the via to other vias. Inthis manner, the current loop formed by the signal via and the groundvia includes a minimal cross-sectional area, and thus a minimalinductive coupling is generated.

In the center area, as mentioned, at least one ground terminal surfacecan be provided, whose area is greater than the areas of the otherterminal surfaces. In this manner, an improved shielding is providedbetween the terminal surfaces of different filter and signal connectionsdisposed in the edge area.

Good decoupling between the first and second filters or the filterterminal surfaces thereof is achieved if the corresponding filterconnections for different filters are disposed at opposite edges of thesubstrate. The at least one terminal surface for the signal connectionis then disposed on the third edge of the substrate.

The component can include one, two, or three connections that arebalanced to each other with respect to ground. As the number ofconnections balanced to ground increases, the number of terminalsurfaces required for the same also increases. A component having oneconnection that is balanced to ground requires at least seven terminalsurfaces disposed in the edge area, or, assuming that an additionalground terminal surface is provided opposite the terminal surface forthe signal connection, then actually, eight.

A component having two connections that are balanced to ground requiresat least eight terminal surfaces disposed in the edge area, while acomponent having three connections that are balanced to ground requiresat least nine such terminal surfaces. In addition, there is the at leastone additional ground terminal surface that is advantageously presentand disposed in the center area, so that a corresponding total number ofterminal surfaces results. It is advantageous if at least those terminalsurfaces disposed in the edge area are symmetrical to each other withregard to their arrangement or grid, wherein at least one plane ofsymmetry is advantageously given. Terminal surfaces disposed in the edgearea are disposed in rows and/or columns of at least three, butpreferably a maximum of four terminal surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention is explained in more detail usingexample embodiments and the associated figures. The figures are purelyschematic and are not true to scale, so that neither absolute norrelative dimensions should be taken from them.

FIGS. 1A through 1C show three different embodiments of a component inschematic cross section;

FIGS. 2A through 2C show terminal surfaces for a component havingconnections that are exclusively unbalanced with respect to ground;

FIGS. 3A through 3C show arrangements of the terminal surfaces for acomponent having a connection that is balanced to ground;

FIGS. 4A through 4F show arrangements of the terminal surfaces for acomponent having two connections that are balanced to ground; and

FIGS. 5A through 5C show arrangements of the terminal surfaces for acomponent having three connections that are balanced to ground.

The following list of reference symbols can be used in conjunction withthe drawings:

-   -   FS Filter substrate    -   F1 First filter    -   F2 Second filter    -   SU Substrate    -   SA Signal terminal surface    -   FA Filter terminal surface    -   MA Ground terminal surface    -   FS Common filter substrate    -   V Via

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

The electrical component is characterized by a common substrate SU,which has the indicated terminal surfaces on its bottom side. The firstand second filter F1, F2 can be disposed, as shown in FIG. 1A, asseparate discrete components on the surface of the substrate SU, andelectrically conductively connected to the same. The substrate SUincludes at least one dielectric layer, which has terminal surfaces onthe bottom side and contact surfaces for the filter or filters on thetop side. The top and bottom sides are electrically conductivelyconnected by connections, and in particular by the denoted vias V (shownas dashed lines in FIG. 1) which are routed in the interior of thesubstrate. The substrate is advantageously formed having multiplelayers, wherein a metallization plane having a structured metallizationthat can implement a circuit, is disposed between every two dielectriclayers. The substrate can be made of a circuit board material, polymer,or ceramic, and is advantageously formed from a low-distortion LTCCceramic (low temperature cofired ceramic) or of an HTCC (hightemperature cofired ceramic).

The multilayer design of the substrate SU also allows the integration ofpassive component functions in the substrate by correspondingstructuring of the metal surfaces and conductors in the metallizationplanes. It is thus possible that the multilayer substrate hascapacitances and inductances in addition to resistors. The passivecomponents can also be connected in a suitable manner such that theinterconnection can be used to implement additional circuits havingcomponent functions. It is possible, for example, to implement simplefilter circuits using integrated LC elements (inductors and capacitors).Thus one of the two filters (F2) can include LC components as shown inFIG. 1B, or be made exclusively of such components, which are integratedin the substrate SU. The other filter F1 is then preferably implementedas a discrete filter component mounted on the surface of the substrate.FIG. 1B shows such an arrangement having a second filter F2 integratedin the substrate, and a first filter F1 mounted on the substrate.

It is also possible to form the two filters on a common piezoelectricalfilter substrate FS, which is mounted on the surface of the substrateSU, as shown in FIG. 1C.

For all illustrated embodiments, the vias that connect the filters andthe terminal surfaces to each other are preferably routed through thesubstrate SU in a straight line. It is, however, also possible that theconnection between the filter and the terminal surfaces is made by atleast two partial vias, each penetrating through only a part of thelayers of the multilayer substrate, and connected to each other by meansof a transverse segment disposed within a metallization plane. Thepartial vias can, therefore, be laterally relative offset to each other.

FIG. 2 shows a top view of the terminal surfaces on the substrate bottomfor a component having exclusively connections that are unbalanced toground. In all embodiments in FIG. 2, arrangements of 3×3 terminalsurfaces are shown. It is also possible, however, to provide a greaternumber of terminal surfaces, which, however, comes at the expense of thesize of the terminal surfaces and/or the area required on the bottomside.

In the embodiment according to FIG. 2A, the terminal surface SA assignedto the signal connection is disposed in the center of the substrate edgeshown at the top of the illustration. The first and second filters eachhave a filter connection FA1, FA2, disposed on opposite sides of thesubstrate bottom and preferably centered there. All terminal surfacesdisposed in the center are adjacent to ground terminal surfaces on bothsides along the edges. In addition, as shown, a ground terminal surfaceMA can also be disposed in the center area, that is, not adjacent to theedge.

FIG. 2B shows an alternative arrangement, in which each terminal surfaceFA1, FA2 for the first and second filters is disposed on opposite edgesof the substrate bottom, wherein the first filter connection FA1 iscentered, and the second filter connection FA2, in contrast, is disposedin the lower right corner. The terminal surface SA assigned to thesignal connection is disposed on a third edge, and centered there. Atthe positions missing from the 3×3 grid, ground terminal surfaces MA areprovided, which are no longer specially designated as such in FIGS. 2Band 2C. Even though all terminal surfaces disposed in the edge area areshown here having the same size, they can, however, deviate therefrom.In particular, it is possible that the terminal surface for the firstfilter disposed closer to the signal connection SA has a smaller surfacearea than the terminal surface FA2 of the second filter F2, disposedfurther away from the signal terminal surface SA.

In the arrangement according to FIG. 2C, the positions for the terminalsurfaces of the first and second filters are exchanged, and thearrangement is a minor image.

FIG. 3 shows the arrangement of terminal surfaces for a component havingexactly one connection that is balanced to ground. The one connectionbalanced to ground can be assigned to the first filter F1, the secondfilter F2, or the signal connection, and includes two terminal surfacesaccordingly. Both terminal surfaces of the connection balanced to groundare preferably formed directly adjacent to each other and of equal size.It is also possible, however, that different terminal surfaces of thesame connection (balanced to ground) have different surface areas.

FIG. 3A shows an arrangement having a connection FA1 that is notbalanced to ground for a first filter F1, disposed at the center of asubstrate edge, and a connection FA2 balanced to ground for the secondfilter F2 at an opposite edge of the substrate. The terminal surface forthe signal connection SA is disposed at the center of the third edge.FIG. 3B shows a variant wherein the connection that is balanced toground is assigned to the first filter.

The arrangements shown in FIGS. 3A and 3B are based on a 3×3 grid. InFIG. 3C, in contrast, the signal connection is formed to be balanced toground, and, therefore, includes two terminal surfaces SA disposed atthe center of an edge. Filter connections FA1 and FA2 are disposedopposite each other at second and third edges, preferably centered, andenclosed on both sides by ground terminal surfaces MA. A single groundterminal surface or two ground terminal surfaces (not shown) for reasonsof symmetry, can be provided at the edge opposite the signal terminalsurfaces SA. Because the ground terminal surfaces can be connected toeach other, it is possible in general in all embodiments to combinesmaller, directly adjacent ground terminal surfaces into one largerground terminal surface.

FIG. 4 shows the arrangement of the terminal surfaces on the substratebottom for components having two connections balanced to ground. In FIG.4A, the first and second filter connections FA1 and FA2 are each formedto be balanced to ground, and disposed at opposite substrate edges sothat both terminal surfaces balanced to ground are directly adjacent toeach other. The signal connection that is not balanced to ground isprovided at the center of a third edge. Because the first and secondfilter connections FA1, FA2 are each adjacent to a ground terminalsurface on both sides along a substrate edge, the number of terminalsurfaces disposed adjacent to each other along the edge is four, whichapplies to both opposite sides. The substrate edge having the signalconnection SA includes only three terminal surfaces disposed parallelthereto, as does the opposite substrate edge.

In FIG. 4B, the signal connection SA and the second filter connectionFA2 are formed to be balanced to ground, and the first filter connectionFA1, in contrast, is not balanced to ground. The same applies to thearrangement according to FIG. 4C. FIG. 4B and FIG. 4C differ from eachother only in that in FIG. 4C, the filter connection FA1 not balanced toground is further away from the signal connection SA than in FIG. 4B.This is achieved in that the first filter connection FA1 is disposed atthe second or third position in a column including four terminalsurfaces.

In FIGS. 4D and 4E, the signal connection SA and the first filterconnection FA1 are designed to be balanced to ground, and the secondfilter connection FA2, in contrast, is not balanced to ground. Similarto the pair of possible arrangements according to FIGS. 4B and 4C, thearrangements according to FIGS. 4D and 4E differ in the position of thesecond filter connection FA2 that is not balanced to ground, which isfurther away form the signal connection SA in FIG. 4E than in FIG. 4D.

FIG. 4F shows a further possibility, wherein the first and second filterconnections FA1, FA2 are formed to be balanced to ground, and the signalconnection SA, in contrast, is not balanced to ground. All connectiontypes are disposed centered along a substrate edge, wherein the firstand second filter connections are disposed at opposite substrate edges,and the terminal surface for the signal connection SA is disposed at athird substrate edge. Although, as previously mentioned, symmetry of theterminal surfaces is not absolutely required, nevertheless a lowernumber of terminal surfaces is shown for symmetry reasons in FIG. 4Fthan in the other embodiments. All embodiments shown in FIG. 4 arecharacterized by a ground terminal surface MA disposed centrally in thecenter area of a substrate bottom, which can include two to four gridpositions of a 3×4 or 4×4 grid.

FIG. 5 shows three different embodiments for components having threeconnections balanced to ground. In FIG. 5A, the first and second filterconnections FA1, FA2 are disposed opposite each other, and each centeredon a substrate edge. The signal connection SA is also disposed in thecenter of the third substrate edge. In FIG. 5B, the two terminalsurfaces of the second filter connection FA2 are further away from thesignal connection SA than the terminal surfaces of the first filterconnection FA1. In the arrangement according to FIG. 5C, the terminalsurfaces of the first filter connection FA1 are further away from thesignal connection SA than those of the second filter connection FA2. Inthe embodiments according to FIGS. 5B and 5C, in each case one filterconnection is disposed in a corner of the substrate bottom, while in allembodiments according to FIGS. 4 and 5A all corners of the substratebottom are occupied by ground terminal surfaces.

The invention is not limited to the arrangements of terminal surfacesshown in the embodiments. Rather, in nearly all embodiments, a greateror lesser number of terminal surfaces can be provided, and a pluralityof terminal surface sizes can be provided, so that at least two terminalsurfaces of different sizes are implemented for the first and secondfilter connections and/or for the signal connection in one component.The advantage of large ground terminal surfaces has already beenexplained, so that the advantage can be accommodated by correspondingenlarged ground terminal surfaces.

Components including a terminal surface arrangement according to theinvention can be optimized for maximum selection and insulation. Here,insulation levels of greater than 50 dB can thereby be achieved, becausethe electromagnetic crosstalk along and between the signal paths can beminimized. The proposed arrangement deviates for the first time fromrigid, specifically prescribed arrangements of terminal surfaces on thesubstrate bottom, because their size, number, and arrangement has beenconsidered for the first time in the component design for minimizingcrosstalk.

Using the components according to the invention, component sizes smallerthan 3.5 mm×3.5 mm, or correspondingly small component areas, can beachieved in a rectangular embodiment. Contrary to an optimization goalfor known terminal surface arrangements, the connections for the firstand second filter connections are not at a maximum distance from eachother, but nevertheless are well insulated from each other, so that thecomponent achieves a high selection and good insulation.

What is claimed is:
 1. An electrical component comprising: a substratehaving a rectangular bottom surface; a first filter implemented in ormounted on the substrate; a second filter implemented in or mounted onthe substrate; a common signal connection, both the first and secondfilters being connected in parallel to the common signal connection; afirst filter connection at the first filter; a second filter connectionat the second filter, wherein the common signal connection and the firstand second filter connections are disposed on the bottom surface of thesubstrate and are each assigned an individual terminal surface carryinga signal, or a pair of terminal surfaces balanced to each other withrespect to ground, thereby implementing respective componentconnections; and a plurality of ground terminal surfaces disposed on thebottom surface of the substrate; wherein altogether at least seventerminal surfaces are disposed near edges of the rectangular substrate;and wherein at least one of the ground terminal surfaces is disposed ina corner of the substrate bottom and is further away from a terminalsurface of the signal connection than a terminal surface of the filterconnections, wherein at least one filter connection comprises a pair ofterminal surfaces balanced to each other with respect to ground, thatare at different distances from the signal connection and are disposedon the substrate bottom, and wherein the terminal surface of the pairthat is disposed closer to the signal connection comprises a smallersurface area than the respectively other terminal surface of the pair.2. The component according to claim 1, wherein the terminal surfacescomprise an arrangement of at least 3×3 terminal surfaces on thesubstrate bottom.
 3. The component according to claim 1, wherein atleast one signal or filter connection comprises a pair of terminalsurfaces balanced to each other with respect to ground, and wherein thetwo terminal surfaces of each pair are disposed directly adjacent toeach other at an edge of the substrate.
 4. The component according toclaim 1, wherein all terminal surfaces of the signal and filterconnections are disposed along the substrate edge, wherein a groundterminal surface is disposed between terminal surfaces of differentconnections.
 5. The component according to claim 1, wherein the terminalsurfaces disposed near the substrate edge enclose one or more groundterminal surfaces disposed closer, relative to the terminal surfaces, ina direction toward the center of the substrate bottom.
 6. The componentaccording to claim 1, wherein at least one of the ground terminalsurfaces has a greater area than a terminal surface of a signal orfilter connection.
 7. The component according to claim 1, wherein thesignal connection is disposed centered on one of the substrate edges. 8.The component according to claim 1, wherein the signal connection isconnected to an antenna connection, wherein the first and second filterconnections are formed as filter input and/or output, and wherein thecomponent implements a diplexer or a duplexer.
 9. The componentaccording to claim 1, wherein each ground connection is connected to ametallization in a housing or directly to one of the two filters bymeans of a plurality of vias, and wherein each terminal surface of thesignal and filter connections is connected to the corresponding filterby exactly one via.
 10. The component according to claim 1, wherein atleast two of the ground terminal surfaces on the substrate bottom areelectrically conductively connected to each other.
 11. The componentaccording to claim 1, wherein each via connected to a filter connectionis routed directly adjacent to another via connected to a groundconnection, wherein the distance between a via connected to a filterconnection and other vias connected to another filter connection isrelatively greater.
 12. The component according to claim 1, wherein theterminal surfaces of the first and second filter connections aredisposed at opposite edges of the substrate, while one or two terminalsurfaces assigned to the signal connection are disposed at a thirdsubstrate edge.
 13. The component according to claim 1, wherein two orthree connections balanced to each other with respect to ground areprovided.
 14. The component according to claim 1, wherein the firstfilter is mounted on the substrate and the second filter is implementedin the substrate.
 15. The component according to claim 1, wherein thefirst filter is implemented in the substrate and the second filter isalso implemented in the substrate.
 16. The component according to claim1, wherein the first filter is mounted on the substrate and the secondfilter is also mounted on the substrate.
 17. The component according toclaim 16, wherein the first filter and the second filter compriseseparate discrete components on the surface of the substrate.
 18. Thecomponent according to claim 16, wherein the first filter and the secondfilter comprise two filters on a common piezoelectrical filter substratethat is mounted on the substrate.
 19. An electrical componentcomprising: a substrate having a rectangular bottom surface; a firstfilter implemented in or mounted on the substrate; a second filterimplemented in or mounted on the substrate; a common signal connection,both the first and second filters being connected in parallel to thecommon signal connection; a first filter connection at the first filter;a second filter connection at the second filter, wherein the commonsignal connection and the first and second filter connections aredisposed on the bottom surface of the substrate and are each assigned anindividual terminal surface carrying a signal, or a pair of terminalsurfaces balanced to each other with respect to ground, therebyimplementing respective component connections; and a plurality of groundterminal surfaces disposed on the bottom surface of the substrate;wherein altogether at least seven terminal surfaces are disposed nearedges of the rectangular substrate; wherein at least one of the groundterminal surfaces is disposed in a corner of the substrate bottom and isfurther away from a terminal surface of the signal connection than aterminal surface of the filter connections; wherein at least one signalor filter connection comprises a pair of terminal surfaces balanced toeach other with respect to ground, and wherein the two terminal surfacesof each pair are disposed directly adjacent to each other at an edge ofthe substrate; wherein the terminal surfaces disposed near the substrateedge enclose one or more ground terminal surfaces disposed closer,relative to the terminal surfaces, in a direction toward the center ofthe substrate bottom; wherein at least one of the ground terminalsurfaces has a greater area than a terminal surface of a signal orfilter connection; wherein the signal connection is disposed centered onone of the substrate edges; wherein the signal connection is connectedto an antenna connection, wherein the first and second filterconnections are formed as filter input and/or output, and wherein thecomponent implements a diplexer or a duplexer; and wherein each viaconnected to a filter connection is routed directly adjacent to anothervia connected to a ground connection, wherein the distance between a viaconnected to a filter connection and other vias connected to anotherfilter connection is relatively greater.
 20. The component of claim 19,wherein at least one filter connection comprises a pair of terminalsurfaces balanced to each other with respect to ground, that are atdifferent distances from the signal connection and are disposed on thesubstrate bottom, and wherein the terminal surface of the pair that isdisposed closer to the signal connection comprises a smaller surfacearea than the respectively other terminal surface of the pair.